/// <summary>
/// Get a list of <see cref="GlyphModelType"/> for a specific string and model-view-projection matrix.
/// </summary>
/// <param name="modelview"></param>
/// <param name="s"></param>
/// <returns></returns>
private List <GlyphModelType> GetGlyphsInstances(Matrix4x4 modelview, string s)
{
ModelMatrix charModel = new ModelMatrix(modelview);
List <GlyphModelType> glyphsInstances = new List <GlyphModelType>();
char[] fontChars = s.ToCharArray();
for (int i = 0; i < fontChars.Length; i++)
{
Glyph glyph;
if (_GlyphMetadata.TryGetValue(fontChars[i], out glyph) == false)
{
continue;
}
// Set instance information
Matrix4x4f modelViewProjection = new Matrix4x4f(
new Vertex4f(charModel.GetColumn(0)),
new Vertex4f(charModel.GetColumn(1)),
new Vertex4f(charModel.GetColumn(2)),
new Vertex4f(charModel.GetColumn(3))
);
Vertex3f glyphVertexParams = new Vertex3f(
glyph.GlyphSize.Width, glyph.GlyphSize.Height,
glyph.Layer
);
Vertex2f glyphTexParams = new Vertex2f(
glyph.TexScale.Width, glyph.TexScale.Height
);
GlyphModelType glyphModel = new GlyphModelType();
glyphModel.ModelViewProjection = modelViewProjection;
glyphModel.VertexParams = glyphVertexParams;
glyphModel.TexParams = glyphTexParams;
glyphsInstances.Add(glyphModel);
// Move next
charModel.Translate(glyph.GlyphSize.Width, 0.0f);
}
return(glyphsInstances);
}
/// <summary>
/// Update eventual buffers required to hold glyph instances information.
/// </summary>
/// <param name="ctx"></param>
/// <param name="glyphsInstances"></param>
private void UpdateGlyphBuffer(GraphicsContext ctx, List <GlyphModelType> glyphsInstances)
{
// Set instances (in case of GL_ARB_draw_instanced and GL_ARB_uniform_buffer_object)
// Note: update only once the uniform buffer
if (_GlyphUniformBuffer != null)
{
_GlyphUniformBuffer.Map(ctx, BufferAccess.WriteOnly);
try {
for (int i = 0; i < glyphsInstances.Count; i++)
{
GlyphModelType glyph = glyphsInstances[i];
string structName = "glo_Glyphs[" + i + "]";
_GlyphUniformBuffer.SetUniform(structName + ".ModelViewProjection", glyph.ModelViewProjection);
_GlyphUniformBuffer.SetUniform(structName + ".VertexParams", glyph.VertexParams);
_GlyphUniformBuffer.SetUniform(structName + ".TexParams", glyph.TexParams);
}
} finally {
_GlyphUniformBuffer.Unmap(ctx);
}
}
// Set instances (in case of GL_ARB_instanced_arrays)
// Note: update only once the array buffer
if (_GlyphInstances != null)
{
_GlyphInstances.Map(ctx, BufferAccess.WriteOnly);
try {
for (uint i = 0; i < glyphsInstances.Count; i++)
{
GlyphModelType glyph = glyphsInstances[(int)i];
_GlyphInstances.SetElement(glyph.ModelViewProjection, i, 0);
_GlyphInstances.SetElement(glyph.VertexParams, i, 1);
_GlyphInstances.SetElement(glyph.TexParams, i, 2);
}
} finally {
_GlyphInstances.Unmap(ctx);
}
}
}
